hildebrandt



Dec. 7,1926. 1,610,007

J. H. HI-LDEBRANDT OIL BURNER Filed August 1'7. 1925 2 Sheets-Sheet 1 611 1101 new Dec. 7 1926. 1,610,007

J. H. HILDEBRANDT OIL BURNER Filed August 17f 1925 2 sheets -sheet 2 3 144mm! 01a attoz nu d suflicient air.

Patented Dec. 7, 1926.

UNITED. STATES PATENT OFFICE.

JULIUSH. HILDEBBANDT, OF CLEVELAND, OHIO.

on; BURNER.

Application filed August 17, 1825. Serial No. 50,595.

degree of heat and the automatic control apparatus has functioned to shut off the 'main supply of oil; The chief'objection to .the use: of an oil ilot, when the main blower is shut' off, is t-e presence of incomplete products of combustion due to the lack of On v the other hand, if the main blower is allowed to function while the main oil supply is shut off, then more oil than is necessary, must be used to keep the flame from-being blown out. Moreover, to permit constant operation of the mainblower involvesan element of expense, which is detrimental to the satisfactory operation of an oil burner.

'Ihe prilicipal object of the present .invention is the provision of means for enabling an oil pilot light to be maintained in operation after the main oil supply has been shut off and to kee such pilot light burning satisfactorily wit out necessitating the operation of the main blower.

I accomplish the above objects by employing a main blowerand an auxiliary or pilot blower with suitable electrical con nections for shutting off one when the other is in operation Moreover, I employ a burner wherein the main supply of air for supporting combustion, as well as that which is used in connection with the operation of the pilot, is caused to flow through the same burner conduit whereby the surface across which the oil is flowing can be maintained clean and free from obstruction'at all times.

Referring now to the drawings, Fig. 1 shows diagrammatically a furnace having an oil burner which is equipped with apparatus made in accordance with my invention; Fig. 2 is a plan view of the burner and operating mechanism apart from the furnace; Fig. 3 is a plan view partly in section, of the main and pilot air conduits showing the junction therebetween; Fig. 4 is a vertical section through the oil distributor; and Fig. 5 is a schematic wiring diagram showing after thelburner has heated a room to the desired the electrical connections which may be employed for operating the blower motors.

Referring now to Fig. 1, indicates a furnace having a grate 11 and an ashpit door opening 12 which are made in the usual way. Supported upon the grate I have shown a burner 13 which may be any form of burner, but as illustrated, is one which is shown and described in Patent No. 1,570,448 issued to me January 19, 1926. Oil may be supplied to the burner from tank 15 through main pipe 16. An adjustable valve 17 may control the quantity of oil which is owing to the burner while the second valve 18 in the by-pass 19 may control the quantity of oil which is allowed to flow into the burner when the pilot lightis in operation. An automatically controlled stop valve 20 functions to stop and start themain oil supply in accordance with temperature requirements, while the 'valve 18 after being once adjusted to the desired amount, remains undisturbed independently of whether or not oil is flowing through the valve 20.

The by-pass 19 as well as the main supply line 16 leads into a fuel supply conduit 21 which is shown in Fig. 4 as being connected to a distributor 22. From the distributor oil may flow down spaced passageway 23, then through passageway 24, and fal upon the bafiie 25 shown in Fig. 1. Accordingly the same passageways are used for the flow of oil during the operation of the main oil supply and of the pilot oil su ly. i ie air for supporting combustion may then upwardly through the grate communieating with conduit 36 which surrounds the oil pipe 21.

The air from the pilot blower may flow through air ipe 37 which merges with the pipe 35 pro erably at a point outside the furnace. At the junction of the two air pipes, I have shown a valve 38 which may moved by pneumatic pressure to entirely close the opening in the pipe 37 when the main blower is in Operation. .Theuse of such valve prevents the escape of air rearwardly through-the pipe 37 when the main blower is in operation. On the other hand the diminutive size of the pilot blower is such that the pressure created thereby is not suflicient to necessitate an entire closing of the pipe 35 through the blower 30 when the pilot blower only is in operation. Consequently I have shown the valve ,38 as being Suflicient in size only to close the opening across the pipe 37, but not suflicient to close the opening in the pipe 35 when in the position indicated by the broken lines 38 in a Fig. 3.

The control mechanism which I employ is such that the main blower is in operation when the pilot blower is stopped and that the pilot blower is in operation when the main blower is stopped. Moreover, the control mechanism is such that the pilotoil supply is always on, while the main oil supply is turned on or oil in accordance with the temperature requirements. To accomplish this, I have shown a thermostat which may be indicated in general at 40 and which may be electrically connected to a control mechanism 41 which functions to operate a switch 62 when the temperature reaches a predetermined degree. In Fig.- 5, the switch 1s shown as comprising a single pole, double throw switch with connections so made that the main motor 32 is on when the pilot motor 33 is off. F or example in Fig. 5 the full line position of the switch 42 enables current to flow from the source of supply 45- through line 46, switch arm 47, contacts 48, line 49, motor 32, line 50 and back to the source of supply. When the switch is in the position shown by the dotted lines 42, then current flows through line 46, switch arm 51, contact 52, line 53, pilot motor 33, line 54, line .50 and back to the source of supply.

Whilethe main blower isin operation, the valve 20 is maintained in open position by means of a mechanical connectionbetween the valve and the switch 42. This connection is shown as a chain 55, one end of which is connected to arm 56 on the switch shaft 57, and the other end of which isconneoted to a lever 58 which operates the valve 20. When the position of the switch is changed to energize the pilot motor, then the valve 20 is moved to closed position by means of a weight 59, shown in Eig. 1, In this way, the main oil supply is shut off when the main blower is stopped but is turned on when the main blower is placed in operation. In the meantime, the oil pilot valve remains open for supplying oil to the pilot light so that there is a constant out any moving parts within the furnace and without any complicated mechanism outside the furnace. vThe chief objection, namely,

the presence of incomplete products of combustion in the furnace. chamber has been entirely overcome, and the operation costs have been reduced to a minimum. The use of the pilot blower has permitted the utilization of an adequate oil pilot flame and has obviated the necessity for a gas pilot, I thus produce an extremely simple burner which enables the air to be controlled independently of the oil and thereby permits efiicient operation under difi'erent conditions.

I claim:

1. In an oilburner the combination with an air conduit, of a main air supply blower and a' pilot air supply blower, an air pipe leading from one of said blowers to the conduit, a second air pipe leading from the other blower and connected tothe first mentioned pipe, and a valve adjacent the connection of said pipes, said valve functioning to be moved by pneumatic pressure to close the opening leading to one of the pipes when one-of the blowers is in operation.

'2. In combination an oilburner adapted to be mounted within a furnace, an oil supply conduit leading upwardly through the center of the burner, an oil distributor carried by the burner and operatively connected to the oil pipe, an air conduit surrounding the oil supply pipe and terminating at one end adjacent the distributor, the other endof the conduit leading outwardly from the furnace, a main blower having an outlet conduit connected to the air conduit, and a pilot air blower having an outlet conduit connected to said air conduit, a valve adjacent the connection of the pilot blower conduit with the air suppl conduit, said valve functioning to close the pilot blower conduit when the main blower is in operation, a main oil supply valve, and a pilot oil supply valve, means for closing the main oil supply valve, when the main blower is 'stopped and for simultaneously starting the pilot blower, said ilot oil supply valve being open indepen ently of the position of the main oil supply valve.

3. In combination, an oil burner having an oil distributor, a main oil supply conduit and a pilot oil supply conduit having a common outlet in said distributor, a main and a pilot air supply, a common air conduit leading from the main and pilot air supplies and terminating adjacent said (listributor and a valve associated with said air supply conduit for automatically cutting ofl' the passage of air from one source of air supply when the other is in operation, and means for automatically stopping the 10 inaifi oilsupply when the main air supply 1s 0 In testimony ivhereof, I hereunto affix my signature.

JULIUS H HILDEBRANDT. 

